package com.weiter.common.core.utils.ip;

import cn.hutool.core.io.FileUtil;
import cn.hutool.core.io.resource.ClassPathResource;
import cn.hutool.core.util.ObjectUtil;
import com.weiter.common.core.exception.UtilException;
import org.lionsoul.ip2region.xdb.Searcher;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;

/**
 * 离线查询IP地址
 * @author weiter
 */
public class RegionUtil {

    private static final Logger log = LoggerFactory.getLogger(RegionUtil.class);

    private static final Searcher SEARCHER;

    static {
        String fileName = "/ip2region.xdb";
        File existFile = FileUtil.file(FileUtil.getTmpDir() + FileUtil.FILE_SEPARATOR + fileName);
        if (!FileUtil.exist(existFile)) {
            ClassPathResource fileStream = new ClassPathResource(fileName);
            if (ObjectUtil.isEmpty(fileStream.getStream())) {
                throw new UtilException("IpAddressUtil初始化失败，原因：IP地址库数据不存在！");
            }
            FileUtil.writeFromStream(fileStream.getStream(), existFile);
        }

        String dbPath = existFile.getPath();

        // 从 dbPath 加载整个 xdb 到内存
        byte[] cBuff;
        try {
            cBuff = Searcher.loadContentFromFile(dbPath);
        } catch (Exception e) {
            log.error(e.getMessage());
            throw new UtilException("IpAddressUtil初始化失败，原因：从ip2region.xdb文件加载内容失败");
        }
        // 使用上述的 cBuff 创建一个完全基于内存的查询对象
        try {
            SEARCHER = Searcher.newWithBuffer(cBuff);
        } catch (Exception e) {
            log.error(e.getMessage());
            throw new UtilException("IpAddressUtil初始化失败");
        }
    }

    /**
     * 根据IP地址离线获取城市
     * @param ip IP地址
     * @return 城市信息
     **/
    public static String getCityInfo(String ip) {
        try {
            ip = ip.trim();
            // 执行查询
            String region = SEARCHER.search(ip);
            return region.replace("0|", "").replace("|0", "");
        } catch (Exception e) {
            log.error("IP地址离线获取城市异常 {}", ip);
            return "未知";
        }
    }
}
